Renesas M32R-FPU - Manual (Page 183)

APPENDICES
APPENDICES-25 M32R-FPU Software Manual (Rev.1.01)
(2) When underflow occurs in Step 1
<When EU = 0, DN = 1: UDF occurs>
Type of R0 Condition FMUL + FADD Operation FMADD Operation
Normalized – R0 = R0 + 0 Same as left
number, 0,
Infinity
Denormalized – R0 = 0 Same as left
number
QNaN – R0 = maintained (QNaN) Same as left
SNaN EV=0 R0 = R0 converted to QNaN Same as left
IVLD occurs
EV=1 R0 = maintained (SNaN) Same as left
IVLD occurs, EIT occurs
<When EU = 0, DN = 0: UDF and UIPL occur>
Type of R0 Condition FMUL + FADD Operation FMADD Operation
Normalized – EIT occurs when FMUL is EIT occurs,
number, 0, completed R0 = maintained
Infinity R0 = maintained
Denormalized – Same as above Same as above
number
QNaN – Same as above Same as above
SNaN EV=0 Same as above IVLD occurs,
EIT occurs
R0 = maintained
EV=1 Same as above Same as above
<When EU = 1: UDF occurs>
Type of R0 Condition FMUL + FADD Operation FMADD Operation
Normalized – EIT occurs when FMUL is EIT occurs,
number, 0, completed R0 = maintained
Infinity R0 = maintained
Denormalized DN=0 Same as above UIPL occurs,
number EIT occurs
R0 = maintained
DN=1 Same as above EIT occurs
R0 = maintained
QNaN – Same as above Same as above
SNaN EV=0 Same as above IVLD occurs,
EIT occurs
R0 = maintained
EV=1 Same as above Same as above
APPENDIX 6
Appendix 6 M32R-FPU Specification Supplemental Explanation